Track working machine

Abstract

A track working machine comprises a machine frame extending in a longitudinal direction and having opposite ends, the machine frame having an upwardly recessed portion between the ends, and undercarriages supporting the machine frame ends on the track for mobility thereon in an operating direction. An operator's cab has an access below the upwardly recessed machine frame portion for permitting an operator to enter and leave the cab, and two structural parts are attached to the machine frame and extend in the longitudinal direction below the upwardly recessed machine frame portion, the structural parts being spaced from each other transversely to the longitudinal direction and defining therebetween a delimited working area. A hoisting apparatus is mounted on the machine frame, the hoisting apparatus comprising a load carrying device and drives for adjusting the load carrying device in vertical, longitudinal and transverse directions.

What is claimed is: 
     
       1. A track working machine comprising (a) a machine frame extending in a longitudinal direction and having opposite ends, (1) the machine frame having an upwardly recessed portion between the ends,     (b) undercarriages supporting the machine frame ends on the track for mobility thereon in an operating direction,   (c) two structural barrier parts attached to the machine frame and extending in the longitudinal direction below the upwardly recessed machine frame portion, the structural parts being spaced from each other transversely to the longitudinal direction and defining therebetween a delimited working area,   (d) an operator's cab having an access directly to and from the working area below the upwardly recessed machine frame portion for permitting an operator to enter and leave the cab, and   (e) a hoisting apparatus mounted on the machine frame, the hoisting apparatus comprising (1) a load carrying device and   (2) drive means for adjusting the load carrying device in vertical, longitudinal and transverse directions.     
     
     
       2. The track working machine of claim 1, wherein the two structural barrier are spaced from each other a maximal distance within an area defined by a transverse section of the machine frame, one end of the structural parts extending to the access of the operator's cab. 
     
     
       3. The track working machine of claim 1, wherein the structural barrier are railings detachably mounted on the machine frame. 
     
     
       4. The track working machine of claim 1, wherein the structural barrier comprise railings pivotably mounted on the machine frame. 
     
     
       5. The track working machine of claim 1, wherein the hoisting apparatus is a crane comprising a boom vertically adjustable by the drive means and pivotal about a vertical axis, the load carrying device being mounted on a free end of the boom. 
     
     
       6. The track working machine of claim 5, further comprising guide rails mounted atop the machine frame and flanged rollers supporting the crane on the guide rails. 
     
     
       7. The track working machine of claim 6, wherein the guide rails extend from one of the machine frame ends at least to the upwardly recessed machine frame portion above the delimited working area. 
     
     
       8. The track working machine of claim 5 wherein the upwardly recessed machine frame portion comprises two beams extending in the longitudinal direction, the beams being spaced from each other transversely to the longitudinal direction and defining therebetween an access opening for receiving the free boom end and the load carrying device mounted thereon. 
     
     
       9. The track working machine of claim 1, wherein the operator's cab is mounted below the upwardly recessed machine frame portion at a distance from the undercarriages, the cab defining a rear end of the delimited working area in the operating direction, and further comprising a tamping unit and a rail lifting unit, the tamping and rail lifting units being vertically adjustably mounted on the machine frame behind the cab in the operating direction. 
     
     
       10. The track working machine of claim 1, further comprising trailers pivotally coupled to the machine frame ends and supported on the track by undercarriages, each one of the trailers carrying track working means and an operator's cab. 
     
     
       11. The track working machine of claim 10, wherein a leading one of the trailers in the operating direction carries a vertically adjustable ballast plow arrangement and has a loading platform, and a rear one of the trailers in the operating direction carries a vibratory track stabilization unit and a vertically adjustable ballast broom. 
     
     
       12. The track working machine of claim 1, comprising a loading platform immediately adjacent the upwardly recessed machine frame portion.